For two or three days rumors had reached General Frost that Captain Lyon was preparing to attack his encampment, and these rumors were so numerous and persistent, that Frost, on the morning of May 10th, addressed a letter to Captain Lyon referring to these ominous reports and wishing to know if there was any truth in them; also declaring that neither he nor his command intended any hostility “towards the United States, or its property or representatives.” How Frost could say this is a mystery. In January he secured from the disloyal Major Bell the pledge that he would not defend the Arsenal against State troops and so reported to Governor Jackson; in April he was in conference with the Governor and chief secessionists of St. Louis; in a formal memorial he had already prayed the Governor to authorize him to form a military encampment near the city, and advocated placing it on the heights above the Arsenal; immediately thereafter the Governor in an autograph letter, sent by two of the secessionists with whom he and Frost had been plotting to take the very property of the United States that Frost now declared he had no intention of touching, solicited personally from Jefferson Davis cannon to be planted on those heights, where Frost contended that his encampment should be formed. This very loyal man a little later went straight into the rebel army. He evidently went to his own place. On June 12th, 1861, he openly proclaimed himself a rebel.[24] In December of that year he was doing for the Southern Confederacy the work of a spy at St. Louis.[25] The sandy-haired, blue-eyed Captain at the Arsenal knew Frost’s real character; and did not deign to answer his letter that was so full of professed loyalty to the United States. All of Lyon’s forces were at noon gathered at the Arsenal and ready to do his bidding. About two o’clock he divided his brigade into three detachments and ordered them to proceed by different routes to Camp Jackson. Two of them went on different streets up through the central part of the city, one along its western boundary. They arrived simultaneously on different sides of the camp and took possession of every approach to it. The artillery took positions on the higher points of ground around the encampment. The whole movement was executed with skill and precision. Lyon now sent a communication to Frost, setting forth what he considered to be the real character of his camp. He demanded the immediate and unconditional surrender of his entire command. He gave him thirty minutes to decide what he would do. Frost now had a brief consultation with his staff. They saw that they were surrounded by a force greatly superior to their own. To fight would be worse than folly. They chose the part of wisdom and surrendered. They turned over to the United States forces all their arms, ammunition, accoutrements and camp equipage.